{ "spore": "profile", "id": "strontium-titanate", "spore_version": "0.2", "family": "oxide-ceramics", "name": "Strontium titanate", "abbreviation": "SrTiO3", "role": "cubic perovskite oxide ceramic and single-crystal substrate", "category": "ceramics", "type": "oxides", "summary": "Strontium titanate (SrTiO3) is a cubic perovskite oxide. A crystal datasheet for Verneuil-grown material gives its density as 5.12 g/cm3 and its melting point as 2353 K. Two product sheets give a melting point of 2060 °C for the powder. Its main commercial use is as a single-crystal substrate for growing oxide thin films and superconducting films.\n", "best_for": "Single-crystal substrates for growing oxide thin films, and thin-film tunable parts that work at low temperature", "weakest_at": "No strength, fracture or toughness value was found. The crystal datasheet gives only a Mohs hardness of 6 to 6.5", "identity": { "formula": "SrTiO3", "cas": "12060-59-2", "crystal_system": "cubic", "space_group": "Pm3m", "designations": [], "source": "ereztech-spec", "where": "Product Name, CAS Number and Molecular formula rows (Ereztech SR0592); cubic crystal system from the Crystal Structure row of azimp-crystal; space group Pm3m from the Wikipedia structure section (printed as Pm 3 m, No. 221)" }, "tags": { "environments": [], "stresses": [], "applications": [ "electronics-and-chips", "optics-and-cameras" ] }, "properties": [ { "benchmark": "density", "label": "Density, Verneuil-grown single crystal", "value": 5.12, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "form": "Verneuil-grown crystal, growth direction near [100]", "temperature": "not stated on the datasheet" }, "method": "Value printed in a crystal supplier datasheet", "status": "ground", "source": "azimp-crystal", "where": "Physical Properties table, Density (g/cm3) row", "source_detail": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point, Verneuil-grown single crystal", "value": 2353, "bound": "exact", "unit": "K", "scope": "material", "conditions": { "form": "Verneuil-grown crystal" }, "method": "Value printed in kelvin in a crystal supplier datasheet", "status": "ground", "source": "azimp-crystal", "where": "Physical Properties table, Melting Point (K) row", "source_detail": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "lattice_constant", "label": "Lattice constant of the cubic cell, Verneuil-grown crystal", "value": 0.39045, "bound": "exact", "unit": "nm", "scope": "material", "conditions": { "form": "Verneuil-grown crystal", "phase": "cubic" }, "method": "Value printed in a crystal supplier datasheet (non-canonical name, see gaps)", "status": "ground", "source": "azimp-crystal", "where": "Crystallographic Properties table, Lattice Constant (nm) row, a = 0.39045", "source_detail": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "hardness_mohs", "label": "Mohs hardness, Verneuil-grown crystal", "value": 6, "value_high": 6.5, "bound": "range", "unit": "-", "scope": "material", "conditions": { "form": "Verneuil-grown crystal" }, "method": "Range printed in a crystal supplier datasheet (non-canonical name, see gaps)", "status": "ground", "source": "azimp-crystal", "where": "Physical Properties table, Hardness (Mohs) row, printed 6-6.5", "source_detail": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "dielectric_constant", "label": "Dielectric constant, Verneuil-grown crystal", "value": 300, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "form": "Verneuil-grown crystal", "frequency": "not stated on the datasheet", "temperature": "not stated on the datasheet" }, "method": "Value printed in a crystal supplier datasheet with no unit", "status": "ground", "source": "azimp-crystal", "where": "Physical Properties table, Dielectric Constant row", "source_detail": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "density", "label": "Density, single-crystal substrate (supplier product page)", "value": 5.11, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "form": "single-crystal substrate, Verneuil method" }, "method": "Value on a supplier product page whose footnote says the product information is based on theoretical data, so it is recorded as calculated", "status": "calculated", "source": "sam-substrate", "where": "Specification table, Density row; footnote under the table", "source_detail": { "title": "Stanford Advanced Materials: Strontium titanate single-crystal substrate product page (catalog CY3345)", "id": "catalog CY3345", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html", "kind": "datasheet", "license": "supplier page, linked not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point, single-crystal substrate (supplier product page)", "value": 2080, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "single-crystal substrate" }, "method": "Value on a supplier product page whose footnote says the product information is based on theoretical data", "status": "calculated", "source": "sam-substrate", "where": "Specification table, Melting Point row", "source_detail": { "title": "Stanford Advanced Materials: Strontium titanate single-crystal substrate product page (catalog CY3345)", "id": "catalog CY3345", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html", "kind": "datasheet", "license": "supplier page, linked not reproduced" } }, { "benchmark": "lattice_constant", "label": "Lattice constant, single-crystal substrate (supplier product page)", "value": 3.905, "bound": "exact", "unit": "Å", "scope": "material", "conditions": { "phase": "cubic perovskite", "form": "single-crystal substrate" }, "method": "Value on a supplier product page whose footnote says the product information is based on theoretical data", "status": "calculated", "source": "sam-substrate", "where": "Specification table, Lattice Constant row, a = 3.905 Å", "source_detail": { "title": "Stanford Advanced Materials: Strontium titanate single-crystal substrate product page (catalog CY3345)", "id": "catalog CY3345", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html", "kind": "datasheet", "license": "supplier page, linked not reproduced" } }, { "benchmark": "dielectric_constant", "label": "Dielectric constant, single-crystal substrate (supplier product page)", "value": 300, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "temperature": "room temperature", "frequency": "1 MHz" }, "method": "Printed as approximately 300 on a supplier product page whose footnote says the product information is based on theoretical data", "status": "calculated", "note": "Printed with a tilde, so the value is approximate.", "source": "sam-substrate", "where": "Specification table, Dielectric Constants row, ~300 (R.T., 1 MHz)", "source_detail": { "title": "Stanford Advanced Materials: Strontium titanate single-crystal substrate product page (catalog CY3345)", "id": "catalog CY3345", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html", "kind": "datasheet", "license": "supplier page, linked not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point, solid (Stanford Advanced Materials safety data sheet)", "value": 2060, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "white to grey powder and pieces, CAS 12060-59-2" }, "method": "Value printed in a supplier safety data sheet, version 2.0", "status": "ground", "source": "sam-msds", "where": "Section III, Melting Point row", "source_detail": { "title": "Stanford Advanced Materials: Material Safety Data Sheet, Strontium titanate", "id": "Version 2.0, revision date Sep 5, 2012; CAS 12060-59-2", "url": "https://www.sputtertargets.net/Public/pdf/strontium-titanate-msds.pdf", "year": 2012, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point, powder (Ereztech product specification)", "value": 2060, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "solid powder, product SR0592" }, "method": "Value printed in a manufacturer's product specification (printed as 2060C)", "status": "ground", "source": "ereztech-spec", "where": "Product specification, Melting point row", "source_detail": { "title": "Ereztech product specification SR0592, Strontium Titanium Oxide", "id": "Ereztech SR0592; CAS 12060-59-2", "url": "https://ereztech.com/product/strontium-titanium-oxide-12060-59-2/?pdf=2446", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "assay_purity", "label": "Assay (purity) of the powder, Ereztech SR0592", "value": 99, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "method": "purity by elemental analysis", "grade": "printed as 99%+" }, "method": "Value printed in a manufacturer's test specification (non-canonical name, see gaps)", "status": "ground", "source": "ereztech-spec", "where": "Test specification, Assay (purity) row, printed 99%+", "source_detail": { "title": "Ereztech product specification SR0592, Strontium Titanium Oxide", "id": "Ereztech SR0592; CAS 12060-59-2", "url": "https://ereztech.com/product/strontium-titanium-oxide-12060-59-2/?pdf=2446", "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "dielectric_peak_temperature", "label": "Diffuse permittivity peak on cooling, undoped sol-gel reference thin film", "value": 60, "bound": "exact", "unit": "K", "scope": "material", "conditions": { "form": "undoped sol-gel thin film on platinized silicon (reference film, not bulk)", "frequency": "10 kHz (Figure 3 caption)" }, "method": "Peak temperature read from the text describing the permittivity against temperature curve of the reference film (non-canonical name, see gaps)", "status": "ground", "source": "okhay2022", "where": "Results, description of Figure 3a (reference ST thin film)", "source_detail": { "title": "Low-Temperature Dielectric Response of Strontium Titanate Thin Films Manipulated by Zn Doping", "id": "doi:10.3390/ma15030859 (Materials 15, 859)", "url": "https://ria.ua.pt/bitstream/10773/36031/1/Mat15%282022%290859-Okhay.pdf", "year": 2022, "kind": "paper", "license": "CC BY 4.0" } } ], "corrosion": [ { "environment": "Strong acids and strong bases", "headline": "The safety data sheet lists strong acids and strong bases as incompatible. No corrosion test was found.", "effect": "Stanford Advanced Materials lists strong acids and strong bases as incompatible materials for strontium titanate. The sheet gives no reaction product, rate or test result.", "rating": "unknown", "conditions": { "basis": "incompatibility list in a supplier safety data sheet", "form": "powder" }, "source": "sam-msds", "where": "Section V (Incompatibility)" }, { "environment": "Water", "headline": "The powder is listed as insoluble in water. The sheet gives no humidity or ageing test.", "effect": "The safety data sheet lists solubility in water as insoluble. No study of ageing or humidity exposure of strontium titanate was found in the sources read in this run.", "rating": "unknown", "conditions": { "basis": "solubility statement only", "form": "powder" }, "source": "sam-msds", "where": "Section III (Solubility in water)" }, { "environment": "Fire and high temperature", "headline": "In a fire the material may emit toxic fumes. The sheet names strontium oxide and titanium oxide as decomposition products.", "effect": "The safety data sheet says the material may emit toxic fumes in a fire and lists strontium oxide and titanium oxide as hazardous decomposition products. It gives no corrosion rate.", "rating": "unknown", "conditions": { "basis": "decomposition products listed in a supplier safety data sheet", "test": "none" }, "source": "sam-msds", "where": "Section IV (Unusual fire and explosion hazards) and Section V (Hazardous decomposition)" } ], "risks": { "hazards": [ { "text": "The Stanford safety data sheet says strontium compounds have a low order of toxicity and that titanium compounds are considered physiologically inert. It also says the oxides and hydroxides of strontium are moderately caustic.", "ghs": [], "source": "sam-msds", "where": "Section VI (Health hazards)" }, { "text": "The same sheet says the dust may be a nuisance dust that causes coughing and shortness of breath, and that it may cause irritation to the skin and eyes.", "ghs": [], "source": "sam-msds", "where": "Section VI (Acute inhalation, skin and eye)" } ], "failure_risks": [ { "mode": "Higher dielectric loss in thin films than in single crystals", "trigger": "Use as a thin film, where point defects, local polar regions and stresses are present", "consequence": "The 2022 paper states that the dielectric loss of thin films is usually considerably higher than that of single crystals, and that it increases as the film gets thinner.", "severity": "moderate", "source": "okhay2022", "where": "Introduction, first paragraph" }, { "mode": "Reaction with strong acids or strong bases", "trigger": "Contact with strong acids or strong bases", "consequence": "The safety data sheet lists both as incompatible and gives no reaction product or rate.", "severity": "low", "source": "sam-msds", "where": "Section V (Incompatibility)" } ], "side_effects": [ { "text": "In a fire the safety data sheet says the material may emit toxic fumes, and that strontium oxide and titanium oxide form as decomposition products.", "affects": "Firefighters and the surrounding area", "source": "sam-msds", "where": "Section IV (Fire) and Section V (Hazardous decomposition)" } ], "handling": [ { "text": "Store in a tightly sealed container and wash thoroughly after handling, per the safety data sheet.", "source": "sam-msds", "where": "Section VII (Hazard label information)" }, { "text": "For spills, use a HEPA filter vacuum, take care not to raise dust, and place the material in a closed container for disposal.", "source": "sam-msds", "where": "Section VII (Steps to be taken in case material is released)" }, { "text": "The sheet recommends a NIOSH approved respirator, impervious gloves, safety glasses and clothing that prevents contact.", "source": "sam-msds", "where": "Section VIII (Protective equipment summary)" } ], "mitigations": [ { "text": "Use local exhaust ventilation to keep exposure low, and recommended mechanical general ventilation, per the safety data sheet.", "source": "sam-msds", "where": "Section VIII (Ventilation)" } ] }, "uses": [ { "application": "electronics-and-chips", "device": "Single-crystal substrate for epitaxial oxide thin films and superconducting films", "example": "The Stanford Advanced Materials product page calls strontium titanate a popular crystal substrate for epitaxial growth of many oxide thin films, and says it is commonly used as a substrate for superconductor thin films.", "source": "sam-substrate", "where": "Product description text" }, { "application": "electronics-and-chips", "device": "Tunable thin-film microwave components", "example": "The 2022 paper in Materials says that ferroelectric-related films are used in varactors, microwave filters, resonators and phase shifters, and that incipient ferroelectrics such as SrTiO3 are useful at cryogenic temperatures for tuning elements.", "source": "okhay2022", "where": "Introduction, first and second paragraphs" }, { "application": "optics-and-cameras", "device": "Special optical windows", "example": "The Stanford Advanced Materials product page lists special optical windows and high-quality sputtering targets among its uses for the material.", "source": "sam-substrate", "where": "Product description text" } ], "supply": [ { "subject": "Strontium (mined as celestite)", "producers": [ { "country": "Iran", "share_percent": 55.6, "year": 2025 }, { "country": "Spain", "share_percent": 22.2, "year": 2025 }, { "country": "China", "share_percent": 17.8, "year": 2025 }, { "country": "Mexico", "share_percent": 4.4, "year": 2025 } ], "critical_lists": [], "recycling": "USGS strontium chapter: Recycling: None.", "substitutes": [ "USGS: barium can be substituted for strontium in ceramic ferrite magnets. No substitute is discussed for electronic perovskite ceramics." ], "source": "usgs-mcs2026-strontium", "where": "World Mine Production and Reserves table, 2025 column (gross weight of celestite in tons, per footnote 6; shares calculated by Space Mushroom against the printed world total of 450,000); Recycling; Substitutes" }, { "subject": "Titanium (sponge metal, the USGS production table)", "producers": [ { "country": "China", "share_percent": 70.3, "year": 2025 }, { "country": "Japan", "share_percent": 14.3, "year": 2025 }, { "country": "Russia", "share_percent": 6.8, "year": 2025 }, { "country": "Kazakhstan", "share_percent": 4.3, "year": 2025 } ], "critical_lists": [], "recycling": "USGS titanium chapter: consumption data for titanium scrap metal were withheld.", "substitutes": [ "USGS: few materials possess titanium metal's strength-to-weight ratio and corrosion resistance. The chapter does not discuss electronic perovskite ceramics." ], "source": "usgs-mcs2026-titanium", "where": "World Sponge Metal Production and Sponge and Pigment Capacity table, 2025 column (sponge metal, not titanium dioxide or mineral concentrates; shares calculated by Space Mushroom against the printed world total of 370,000); Recycling; Substitutes" } ], "media": [], "documents": [ { "title": "Stanford Advanced Materials Material Safety Data Sheet: Strontium titanate, version 2.0 (revision date Sep 5, 2012), hosted by sputtertargets.net", "type": "sds", "url": "https://www.sputtertargets.net/Public/pdf/strontium-titanate-msds.pdf", "year": 2012 }, { "title": "Ereztech product specification SR0592: Strontium Titanium Oxide", "type": "datasheet", "url": "https://ereztech.com/product/strontium-titanium-oxide-12060-59-2/?pdf=2446" }, { "title": "Stanford Advanced Materials product page: Strontium titanate single-crystal substrate (catalog CY3345)", "type": "datasheet", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html" }, { "title": "Crystal datasheet: Strontium Titanate, Verneuil growth (azimp.ru PDF)", "type": "datasheet", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf" }, { "title": "Okhay, Vilarinho and Tkach: Low-Temperature Dielectric Response of Strontium Titanate Thin Films Manipulated by Zn Doping (Materials 15, 859)", "type": "paper", "url": "https://ria.ua.pt/bitstream/10773/36031/1/Mat15%282022%290859-Okhay.pdf", "year": 2022 }, { "title": "USGS Mineral Commodity Summaries 2026: Strontium", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-strontium.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf", "year": 2026 } ], "gaps": [ "No flight, vacuum, radiation, thermal-vacuum or space-environment result for strontium titanate was found in any source read in this run, so no environments tag is given.", "No GHS hazard codes are recorded. The PubChem record could not be read (the site returned a browser check), and the Stanford safety data sheet prints no H-codes.", "The Lorad Chemical product page could not be read by the fetch tools in this run, so its powder density and melting point are not recorded.", "Atomic weights of strontium, titanium and oxygen were not read in a source this run, so the recipe parts carry no atomic_weight.", "The molecular weight is printed without a unit in the Ereztech specification and in the Stanford safety data sheet, so it is left out.", "Strontium abundance in the crust was not found in a source read in this run.", "Strontium was variously included or not included on critical minerals lists, according to the USGS strontium chapter. No list status for this profile was confirmed, so critical_lists is empty. The titanium critical-list status was not checked.", "The titanium figures are for titanium sponge metal. Titanium dioxide and mineral concentrate production were not read, so they are not recorded.", "The thermal expansion and loss tangent values are printed with exponents in the crystal datasheet and the supplier product page, so they are left out.", "Mohs hardness: Wikipedia gives a different value for synthetic material ('Mohs hardness 5.5 for synthetic, 6-6.5 for natural'). Wikipedia is used here only for composition and structure, so only the crystal datasheet's 6 to 6.5 is recorded.", "The supplier product page's values are based on theoretical data, according to its footnote. They are recorded as calculated, and no measured value for the same quantity was found in the sources read here.", "No humidity, ageing or long-term corrosion study for strontium titanate was found. The corrosion entries rest on the safety data sheet's incompatibility list and solubility statement.", "Room-temperature permittivity of a sintered bulk ceramic was not found. The 2022 paper reports thin-film values, and its doped-film values are not recorded because they are for a different composition.", "The non-canonical property names lattice_constant, hardness_mohs, assay_purity and dielectric_peak_temperature are used because the canonical list has no entry for them." ], "story": { "why": "Strontium titanate (SrTiO3, CAS 12060-59-2) is a cubic perovskite oxide that is sold as a powder and as single crystals. Its main commercial role is as a substrate. Crystal suppliers describe it as a popular substrate for growing oxide thin films and superconducting films, and the supplier page also lists special optical windows among its uses.", "uses": [ { "where": "Single-crystal substrates for oxide and superconducting thin films", "line": "The Stanford Advanced Materials product page calls strontium titanate a popular crystal substrate for epitaxial growth of many oxide thin films, and says it is commonly used as a substrate for superconductor thin films." }, { "where": "Tunable thin-film microwave components", "line": "A 2022 paper in Materials says that ferroelectric-related films are used in varactors, microwave filters, resonators and phase shifters. It adds that incipient ferroelectrics such as SrTiO3 are useful at cryogenic temperatures for tuning elements." } ], "can_do": [ { "label": "Substrate lattice", "line": "Serves as a cubic perovskite substrate for oxide films. The supplier product page prints a lattice constant of 3.905 Å and calls it a popular substrate for epitaxial growth.", "benchmark": "lattice_constant", "scope": "material" }, { "label": "Melting point", "line": "Melts at 2060 °C as a powder, per the Ereztech specification, and at 2353 K as a Verneuil crystal, per the crystal datasheet.", "benchmark": "melting_point", "scope": "material", "value": "2060 °C" }, { "label": "Thin-film permittivity peak", "line": "Shows a diffuse permittivity peak near 60 K in an undoped sol-gel reference thin film, according to the 2022 paper.", "benchmark": "dielectric_peak_temperature", "scope": "material", "value": "60 K" }, { "label": "Hardness", "line": "Reaches a Mohs hardness of 6 to 6.5 for a Verneuil crystal, according to its datasheet.", "benchmark": "hardness_mohs", "scope": "material", "value": "6 to 6.5" } ], "compare": "The melting point is reported at two levels. The Ereztech specification and the Stanford safety sheet both give 2060 °C for the powder. The crystal datasheet gives 2353 K, and the supplier substrate page gives 2080 °C, which is the figure the crystal datasheet's 2353 K converts to. Two density figures are on record: 5.12 g/cm3 from the crystal datasheet and 5.11 g/cm3 from the supplier substrate page, which the page footnote says is based on theoretical data. The crystal datasheet prints a dielectric constant of 300 with no temperature or frequency, and the substrate page prints about 300 at room temperature and 1 MHz. The sources read here give no bulk ceramic value.", "compare_rows": [ { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Dielectric constant", "benchmark": "dielectric_constant", "scope": "material" } ], "handling": [ "Store in a tightly sealed container and wash thoroughly after handling.", "Avoid raising dust. Vacuum spills with a HEPA filter and place the material in a closed container for disposal.", "Keep it away from strong acids and strong bases, which the safety sheet lists as incompatible." ], "good_for": [ "Oxide thin-film growth. The supplier page calls it a popular crystal substrate for epitaxial growth of many oxide thin films.", "Low-temperature tunable parts. The 2022 paper says it is useful at cryogenic temperatures for tuning elements." ], "watch_out": [ "Thin films have much higher dielectric loss than single crystals, according to the 2022 paper.", "Hardness is not settled. The crystal datasheet gives a Mohs hardness of 6 to 6.5, and Wikipedia gives a lower Mohs value for synthetic material.", "The supplier substrate values are theoretical, according to the footnote on that page, so they are calculated rather than measured." ], "verdict": "Strontium titanate is a well-recorded oxide substrate. Its melting-point figures differ between suppliers (2060 °C and 2080 °C), and its datasheets give no strength, toxicity or space-environment data, so it is best treated as a substrate and a dielectric material only.", "recipe": { "line": "SrTiO3 is a strontium titanium oxide with the cubic perovskite structure. Its formula is SrTiO3, with one strontium atom, one titanium atom and three oxygen atoms per formula unit. Single crystals are grown by the Verneuil method, according to the crystal datasheet from azimp.", "parts": [ { "name": "Strontium", "symbol": "Sr", "role": "The large cation in the perovskite framework. Strontium is mined as celestite, the strontium mineral named in the USGS summary." }, { "name": "Titanium", "symbol": "Ti", "role": "The smaller cation of the perovskite framework, sitting among the oxygen atoms." }, { "name": "Oxygen", "symbol": "O", "role": "Three oxygen atoms per formula unit complete the framework around the cations." } ] }, "risk_groups": [ { "title": "For people", "lead": "The Stanford safety data sheet gives strontium titanate a low order of toxicity and lists nuisance dust and mild irritation. No GHS hazard codes are recorded for it, and the sheet gives no toxicity values.", "points": [ { "label": "The powder", "line": "The sheet lists the dust as a possible nuisance dust that can cause coughing and shortness of breath, and as a possible irritant to skin and eyes." }, { "label": "Strontium and titanium", "line": "The sheet says strontium compounds have a low order of toxicity and describes titanium compounds as physiologically inert." }, { "label": "Exposure limits", "line": "The sheet lists no OSHA PEL and no ACGIH TLV for the material, both printed as N/A." } ], "level": 1, "verdict": "Low toxicity per the SDS; dust irritates" }, { "title": "If it fails", "lead": "These results come from thin-film measurements and from the safety sheet, not from service incidents.", "points": [ { "label": "Thin films", "line": "The 2022 paper says thin films usually have much higher dielectric loss than single crystals, because of point defects, local polar regions and stresses." }, { "label": "In a fire", "line": "The sheet lists strontium oxide and titanium oxide as decomposition products, and says fumes from a fire are hazardous." }, { "label": "Strong acids and bases", "line": "The sheet lists strong acids and strong bases as incompatible, and gives no reaction data." } ] }, { "title": "Handling and storage", "points": [ { "label": "Keep it sealed", "line": "Store in a tightly sealed container and wash thoroughly after handling. Keep it away from strong acids and strong bases." }, { "label": "Dust", "line": "Use a HEPA filter vacuum for spills and avoid raising dust. The sheet recommends a NIOSH approved respirator, impervious gloves and safety glasses." } ] } ] }, "updated": "2026-11-01", "review": { "status": "draft", "method": "assistant", "checked_values": 13, "unreachable": 3, "caveats": 3, "note": "Read by an AI assistant on 2026-11-01 from the pages and PDFs fetched in that run. Unreachable in that run: the Lorad Chemical product page (no text returned to curl), the PubChem record (browser check page) and the American Elements SDS (HTTP 403). Wikipedia was used for composition, crystal system, space group and history only. Caveats: the supplier product page's values are stated as theoretical in its footnote, so they are recorded as calculated; the crystal datasheet gives Mohs hardness as 6-6.5 without a form; the 2022 paper's values are for thin films." }, "sources": { "azimp-crystal": { "title": "Strontium Titanate crystal datasheet (Verneuil growth, PDF)", "id": "azimp.ru PDF, file SrTiO3_Strontium_Titanate.pdf", "url": "https://azimp.ru/upload/pdf-static/CRYSTAL/SrTiO3_Strontium_Titanate.pdf", "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "ereztech-spec": { "title": "Ereztech product specification SR0592, Strontium Titanium Oxide", "id": "Ereztech SR0592; CAS 12060-59-2", "url": "https://ereztech.com/product/strontium-titanium-oxide-12060-59-2/?pdf=2446", "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "sam-msds": { "title": "Stanford Advanced Materials: Material Safety Data Sheet, Strontium titanate", "id": "Version 2.0, revision date Sep 5, 2012; CAS 12060-59-2", "url": "https://www.sputtertargets.net/Public/pdf/strontium-titanate-msds.pdf", "year": 2012, "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "sam-substrate": { "title": "Stanford Advanced Materials: Strontium titanate single-crystal substrate product page (catalog CY3345)", "id": "catalog CY3345", "url": "https://www.samaterials.com/strontium-titanate-single-crystal-substrate.html", "kind": "datasheet", "license": "supplier page, linked not reproduced" }, "okhay2022": { "title": "Low-Temperature Dielectric Response of Strontium Titanate Thin Films Manipulated by Zn Doping", "id": "doi:10.3390/ma15030859 (Materials 15, 859)", "url": "https://ria.ua.pt/bitstream/10773/36031/1/Mat15%282022%290859-Okhay.pdf", "year": 2022, "kind": "paper", "license": "CC BY 4.0" }, "usgs-mcs2026-strontium": { "title": "Mineral Commodity Summaries 2026, Strontium", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-strontium.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-mcs2026-titanium": { "title": "Mineral Commodity Summaries 2026, Titanium and Titanium Dioxide", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "wikipedia-sto": { "title": "Wikipedia: Strontium titanate (used for composition, crystal system, space group and history only)", "id": "English Wikipedia article, Strontium titanate", "url": "https://en.wikipedia.org/wiki/Strontium_titanate", "kind": "web", "license": "CC BY-SA 4.0" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/strontium-titanate/" }